Safety device for locks



A. COME.- SAFETY DEVICE FOR Loexs.

APPLICATION FILED JULY 161 I920- Patented Sept. 20, 1921.

' attorney UNITED STATES.

VA'TTILIO'CONT'E, or BUENOSAIRES, ARGENTINA.

PATENTIVOFFI SAFETY DEvrcE non LOCKS.

tion.

- This invention relates to an improved safety device for looks whichoffers several advantages over locks of, known construction and whichallows of performing certain operations whereby an ordinary spring latchlock may be used as a key-controlled lock, by which arrangement its useand construction are considerably simplified and rendered lessexpensive,,while obtainingat the same time a higher degree of safety.

This invention substantially consists in providing an ordinary springlatch lock with a pin adapted to lock the latch operating parts byentering into a hole in the shank of the'latch bolt. The pin'is providedwith a projection, and the key-operated cylinder used for operating thelock and which may be of any suitable type, is formed with a helical camadapted toraise said projection and in consequence release "the latchofthe lock. The ,pin passes through a' boss. provided with three groovesin which a stop on the pin is interchangeably engaged, so that threepositions are obtained, corresponding with three operations of the lock,vizz' one in which the lock operates with the key only; a secondposition in whichthe operation is effected by the handle only, and athird position in which the lock is blocked.

In order to facilitate the understanding of the invention, the same hasbeen 'illustrated by way of example in the accompanying drawings,wherein:

Figure 1 illustrates a cross section of a lock constructed in'accordancewith the invention. I

Fig. 2 shows a rear elevatlon of the same;

and

three grooves.

In all the several views, the same reference Application filed M15 is,

CONTE, a sub- Fig. 3 is a horizontal section of the lock,

finger 12 is out of the path of the cam, any

Fig. 4 is a detail view of the boss with its Specif cation of LettersBatent. Pat t d Sept. 20, 1921.

1920. Serial No. 396,740.

way of example and itwill be evident that the same may be'of any othersuitable construction as they-do not form part of this invention. Thecylinder 1 which is to be used when thelock is to be operated. by a key,

has been shown somewhat diagrammatically and is adapted to rotate" whenthe proper key 2 is inserted therein. Said cylinder or thevcorrespondingpart of any other typeof lock is provided withan axially operatinghelical cam 4 formed .on the drum 3.

; The'cover 5 of the lock housing is provided with a hole for thepassage therethrough of a pin 6, guided by the plate 7.

I the lock.

- 18 indicates the springfor projecting the latch bolt, and 20 is thehubror rollback for bolt 11 and operable'by handle 19, while '21 is aspring, arranged to return cylinder 1 to its normal position.

. As has already been stated before, the present. arrangement allowsthelock to be operated under three different conditions which inconnection with the drawings and the foregoing description will be vreadily understood.

Considering the first case, in which the lockis blocked againstoperation by the key or by the handle, it will be seen that theseconditions are obtained by inserting the stop 13 into the groove-14which is of sufiicient depth to permit pin v6 to pass through the hole9'in the shank 10 of the bolt, thereby preventing the handle from beingoperated. Since the groove 14 is so positioned that the turning of thekey will not raise the pin; in consequence, the lock remains blocked orlocked.

' In the second case, the lock can be opened withthe key, but not withthe handle alone.

For this purpose,'the projection 13 is caused to engage with the groove15. The pin still locks the shank but as it has turned to such an extentas to bring finger 12 into the path will shank whereupon the lock may beopened by operating the handle;

Thethird case, finally permits the lock'to' be operated by the handle inthe same. way as an ordinary spring-latch lock, this condition beingattained by placing the stop into the third groove 16 which, being ofless depth than the former two, will hold the pin in its raised positionwith the finger 12 above the cam so that, the shank isthus released.

Having now described my said invention, I declare that what I claim asnew and de sire to secure by Letters Patent, is: o 1. In a'key-operated,spring latch lock, a safety device consisting of a helical cam caused torotate by the action ofthe key, a pin adapted to blockthe latch bolt ofthe lock by penetrating into a hole formed in said bolt, said pin beingprovided with a 7 finger adapted to engage with the cam, so that on therotation-of said cam the pin.

will'be raised, ahandle for operating the latch bolt when released, aboss provided with'three grooves, and a projection formed integral withsaid pin, for interchangeable engagement in said grooves whereby saidpin may be caused to assume an operative positionwherein its finger willbe engage able by said cam, a second operative position in which itsfinger is out of the path of the cam, or a third position 'in jwhich thepin willrbe held raised in inoperative position, substantially asabovedescribed and for the purposes set forth.

2. In'a key-operated, spring latch lock,

the combination,- with thelatch bolt and its operating handle, of amovable key-operated part, a pin engageable with said boltto look i thesame against operatiomsaidpin having a projection thereon, a member onsaid keyoperated part for coaction with said projection to'disengage thepin from the bolt, and means to selectively hold said pin in any one ofthree predetermined positions, in one w 3. A key-operated, spring latchilock ac- V cording to claim 2, in which the-selective holding means.comprise a boss having three angularly-arranged grooves tointerchangeably receive a stop on thepin, the latter being rotatablymounted to shift the stop to position to engage a selected groove.

4. In a key-operated, spring latch lock,

the combination, with the latch bolt and its operating handle, of arotatable key-operated part, a part movable into and out of engagement"with the bolt to lock and unlock the same, coacting means on-thelocking part and the key-operated part to disengage the former from thebolt,fland means for selec tively holdingsaid locking partin any one ofthree predeterminedposltions, in one of whichthe locking part and thebolt are engaged, but the coacting means areinactive,

in the second of which said locking part and said'bolt are still engagedbut thefcoatin'g'means are active, and in the third'of which the lockingpart and the boltare disengaged. In testimony whereof, I hereunto afiix'my signature in presence of two witnessesq j I Witnesses: I. A. DEMARVAL, I FELIPE 'MERLE.

' ATTIILIOCONTE.

